Thanks for the chance to assist on this matter. I am an attorney with over 12 years experience in criminal
That depends on when you leave. If you leave before the start of the trial
then most likely the court
will issue a warrant for your arrest. That warrant will not expire, so if you ever attempt to reenter the country, you can be arrested on the warrant and brought to trial.
If you leave after the start of the the trial, but before the completion, then the court can hold your trial "in absentia" (without you being present). If this happens, they would impose a sentence
as well as a warrant and if you return you could be put in jail for the sentence received.
If you never return to the US, then it is likely nothing would happen, unless this is serious crime (like murder, sexual assault or some other serious felony it is unlikely the state would attempt to extradite you for return.
The problems will start if you return. There is no expiration of a a warrant...so you could leave and return 10 years from now and they could still enforce a pending warrant.